IBM Education Assistance for z/os V2R2

Transcription

1 IBM Education Assistance for z/os V2R2 Item: GRS EQDQ Monitor Enhancements Element/Component: Global Resource Serialization (GRS) Material current as of May 2015

2 Agenda Trademarks Presentation Objectives Overview Usage & Invocation Interactions & Dependencies Migration & Coexistence Considerations Presentation Summary Appendix Page 2 of 27

3 Trademarks See url for a list of trademarks. Page 3 of 27

4 Presentation Objectives Provide you with insight into the function and purpose of GRS EQDQ Monitor Enhancements Page 4 of 27

5 Overview Problem Statement / Need Addressed: Diagnosing ENQ-related errors is difficult without built-in tracing Understanding RESERVEs or the impact of RNLs as well The GRS EQDQ monitor (ISGAUDIT) provides tracing at the cost of ENQ performance, and its user interface is complex Solution / Approach: Captures ENQ/DEQ diagnostics for problem determination while minimizing impact to system performance Uses SMF 87 (introduced in APAR OA42221 to track Global Generic Queue Scans) More cohesive, understandable filtering than EQDQ Monitor Benefit / Value: Provides ability to establish ENQ/DEQ history, filter on certain requests, and aid in problem determination Inherits the power of SMF (e.g. Logstream recording, exits, etc) Page 5 of 27

6 Usage & Invocation How do I activate GRS Monitoring Enable the GRS Monitoring with existing filtering SETGRS MONITOR=YES Disable the GRS Monitoring SETGRS MONITOR=NO Change the active filters and activate SETGRS GRSMON=xx xx corresponds to GRSMONxx Existing MONITOR(YES NO) keyword in GRSCNFxx No GRSMON(xx) analogue in GRSCNFxx How do I know GRS Monitor status? Display GRS[,SYSTEM] shows MONITOR status and current GRSMONxx Page 6 of 27

7 Usage & Invocation You must ensure that SMFPRMxx includes Type 87 How do I activate SMF Tracing of Type 87 in SMFPRMxx? Specify SYS(TYPE(87(1))) for only subtype 1 QSCAN Specify SYS(TYPE(87(2))) for only subtype 2 ENQ/DEQ Specify SYS(TYPE(87)) for all subtypes SMF 87 Recording in V2R2 drives SMF exit IEFU84 (switch from IEFU85 with OA42221) In V2R2, SMF 87 records are no longer cut under the caller's thread Page 7 of 27

8 Usage & Invocation SMF 87 Subtype 1 QSCAN Includes SMF87RHS (Header), SMF87DEF (self defining section), SMF87REQ (Requester section), SMF87QSCAN (Queue scan section) Cut whenever global generic queue scan is issued Introduced to help track queue scan abusers Page 8 of 27

9 Usage & Invocation SMF 87 Subtype 2 ENQ/DEQ Multiple ENQ/DEQ requests per record, cut within 1 SMF interval from time of request Includes SMF87RHS (Header), SMF87DEF (self defining section), SMF87REQ (n Requester sections), SMF87ENQ (n ENQ/DEQ sections) Requester section x corresponds to ENQ/DEQ section x... Page 9 of 27

10 Usage & Invocation Breakdown of an SMF 87 Subtype 2 record (Mapped by ISGYSMFR) SMF87RHS - Header section SMF87DEF - Self defining section SMF87REQ 1 thru n - Requester section contains items like the PSW, JOBNAME, ASID, TCB and time of request Some new fields added that are specific to ENQ/DEQ SMF87ENQ 1 thru n Data Section contains QNAME, RNAME, SCOPE, and other details about the request parameters See Appendix A for more details Page 10 of 27

11 Usage & Invocation GRSMONxx Syntax FILTER INCLUDE EXCLUDE QSCAN keywords QSCAN [ XSYS(YES NO ANY) ] [ GENERIC(YES NO ANY) ] FILTER INCLUDE EXCLUDE ENQ/DEQ keywords ENQ DEQ ENQDEQ QNAME( qnamepattern ) RNAME( rnamepattern ) [ JOBNAME( jobnamepattern ) ] [ SCOPE(STEP SYSTEM SYSTEMS ANY) ] [ AUTHQLVL(2 NONE) ] [ RESERVE(YES NO ANY) ] [ RNLMATCH(YES NO ANY) ] [ WAITER(YES NO ANY) ] Page 11 of 27

12 Usage & Invocation Two logical FILTER lists: Include list and Exclude list like RNLs Exclude list trumps Include list Pattern strings support wildcard characters * and? Both types of FILTER statements can coexist in same member Order does not matter Long Rname support to handle strings greater than one record length RNAME( 'on_your_marks...', 'get_ready...', 'get_set...', 'go!' ) Up to 255 characters excluding quotes and commas Avoid FILTER INCLUDE ENQ QNAME(*) RNAME(*) without other modifiers too much data! Page 12 of 27

13 Usage & Invocation Example: Trace all ENQs and DEQs with a scope of SYSTEMS and Qname of SYSDSN except those from MYJOB Also trace global generic queue scans FILTER INCLUDE ENQDEQ QNAME(SYSDSN) RNAME(*) SCOPE(SYSTEMS) FILTER EXCLUDE ENQDEQ QNAME(*) RNAME(*) JOBNAME(MYJOB) FILTER INCLUDE QSCAN GENERIC(YES) XSYS(YES) Page 13 of 27

14 Usage & Invocation Example: Trace all ENQs and DEQs resulting in a HW RESERVE FILTER INCLUDE ENQDEQ QNAME(*) RNAME(*) RESERVE(YES) Page 14 of 27

15 Usage & Invocation Example: Trace all ENQ requests which matched the RNLs and may have been affected But exclude SYSDSN ENQs FILTER INCLUDE ENQ QNAME(*) RNAME(*) RNLMATCH(YES) FILTER EXCLUDE ENQ QNAME(SYSDSN) RNAME(*) Page 15 of 27

16 Usage & Invocation SYS1.SAMPLIB(ISGMON00) contains more hints and examples Page 16 of 27

17 Interactions & Dependencies Software Dependencies SMF considerations Think about planning SMF resources for new data stream Unlike other SMF records, SMF 87 subtype 2's can be cut in much greater frequency Use a separate logstream for type 87s to avoid running out of space for other types You will likely need to create a program (REXX?) to aggregate the SMF 87 data or use an existing product Hardware Dependencies None Exploiters None Page 17 of 27

18 Migration & Coexistence Considerations None, as this is a single-system solution If you are already using APAR OA42221, the default behavior will be the same, except... SMF 87 Recording in V2R2 drives SMF exit IEFU84 (switch from IEFU85 with OA42221) The Requester section (SMF87REQ) grew in size but that is encapsulated by the self-defining section In V2R2, the Requester Section is version 2 If no GRSMONxx is active, filtering reverts to OA42221 logic Page 18 of 27

19 Presentation Summary GRS EQDQ Monitor Enhancements Tracing ENQs and DEQs via SMF 87 minimal impact to ENQ performance Filtering options in PARMLIB Page 19 of 27

20 Appendix A SMF 87 Subtype 1&2 fields Details: Header Section SMFRCD87 DSECT SMF87RHS DS 0CL24 Record Header Section SMF87LEN DS H Record Length SMF87SEG DS H Segment Descriptor SMF87FLG DS 0CL1 Header Flag Byte SMF87FST EQU X'40' bit 1 - SUBTYPES utilized ORG SMF87FLG+1 SMF87RTY DS CL1 Record Type - 87 SMF87TME DS FL4 Record Written Time SMF87DTE DS CL4 Record Written Date SMF87SID DS CL4 System Identification SMF87SSI DS CL4 Subsystem ID SMF87STP DS H Record Subtype Page 20 of 27

21 Appendix A SMF 87 Subtype 1&2 fields Details: Self Defining Section SMF87DEF DS 0CL20 Self Defining section SMF87DEF_LEN DS F Length of this section SMF87DEF_REQ_OFF DS F Requester section offset SMF87DEF_REQ_LEN DS H Requester section length SMF87DEF_REQ_NUM DS H Number of Requester sections SMF87DEF_QSCAN_OFF DS 0F Qscan section offset SMF87DEF_DATA_OFF DS F Data section offset SMF87DEF_QSCAN_LEN DS 0H Qscan section length SMF87DEF_DATA_LEN DS H Data section length SMF87DEF_QSCAN_NUM DS 0H Number of Qscan sections SMF87DEF_DATA_NUM DS H # of Data sections SMFRCD87_LEN EQU *-SMFRCD87 Page 21 of 27

22 Appendix A SMF 87 Subtype 1&2 fields Details: Requester Section (Page 1) SMF87REQ DSECT SMF87REQ_COMP DS CL8 Requester Component ID SMF87REQ_VERSION DS F Requester section version SMF87REQ_SYS DS CL8 Requester System Name SMF87REQ_STOK DS CL8 Requester SToken SMF87REQ_ASID DS H Requester Asid DS CL2 reserved SMF87REQ_TCB DS A Requester TCB address SMF87REQ_JOB DS CL8 Requester Jobname SMF87REQ_STIME DS CL16 Requester start timestamp SMF87REQ_CTIME DS CL16 Requester completion timestamp SMF87REQ_RC DS F Requester return code SMF87REQ_RSN DS F Requester reason code SMF87REQ_PSW DS CL8 Requester PSW Page 22 of 27

23 Appendix A SMF 87 Subtype 1&2 fields Details: Requester Section (Page 2) SMF87REQ_FLAGS DS 0B Flags SMF87REQ_JOBINIT EQU X'80' Initiated Job. Only valid when SMF87STP is SMF87STP_ENQ SMF87REQ_STCTSU EQU X'40' Started Task. Only valid when SMF87STP is SMF87STP_ENQ ORG SMF87REQ_FLAGS+1 SMF87REQ_AUTH1 DS B copy of CDATTR2. Only valid when SMF87STP is SMF87STP_ENQ DS CL2 SMF87REQ_SMFID DS CL4 System id. Only valid when SMF87STP is SMF87STP_ENQ SMF87REQ_PROGRAMNAME DS CL8 Program Name. Only valid when SMF87STP is SMF87STP_ENQ SMF87REQ_LEN EQU *-SMF87REQ Page 23 of 27

24 Appendix A SMF 87 Subtype 2 fields Details: ENQ/DEQ Section (Page 1) MF87ENQ DSECT MF87ENQ_EYE DS CL8 service eye-catcher MF87ENQ_VERSION DS F enq section version MF87ENQ_REQUESTFIELDS DS 0CL8 MF87ENQ_FLAGS1 DS 0CL1 MF87ENQ_REQWAITED EQU X'80' When on, this request was queued to wait for the resource MF87ENQ_EXITCHANGED EQU X'40' When on, this request was changed by an exit MF87ENQ_INCLUDED EQU X'20' When on, this request was included by RNLs MF87ENQ_EXCLUDED EQU X'10' When on, this request was excluded by RNLs MF87ENQ_CONVERTED EQU X'08' When on, this request was converted by RNLs MF87ENQ_PCREQUEST EQU X'04' When on, this request was a result of a PC-ENQ, PC-DEQ, or ISGENQ MF87ENQ_RNLNO EQU X'02' When on, this request was made requesting no changes be allowed by RNLs MF87ENQ_LIST EQU X'01' When on, this request was part of a list request Page 24 of 27

25 Appendix A SMF 87 Subtype 2 fields Details: ENQ/DEQ Section (Page 2) SMF87ENQ_FLAGS2 DS 0CL1 SMF87ENQ_DIRECTEDTCB EQU X'80' When on, this request was directed to another TCB SMF87ENQ_STEPMUSTCOMPLETE EQU X'40' When on, this request asked for Step must complete SMF87ENQ_SHARE EQU X'20' When on, this request was for shared access SMF87ENQ_RESERVE EQU X'10' When on, this request was for a RESERVE SMF87ENQ_OBTAIN EQU X'08' When on, this request was to obtain or change an ENQ. When off, this request was to release an ENQ ORG SMF87ENQ_FLAGS2+1 SMF87ENQ_SCOPE DS X Final scope of the request SMF87ENQ_RNAMELEN DS X Rname length SMF87ENQ_REQUESTTYPE DS X Type of request DS CL3 SMF87ENQ_DEVICEINFO DS 0CL8 SMF87ENQ_DEVN DS BL2 Device number SMF87ENQ_UCBVOLI DS CL6 VolSer if UCB avail. SMF87ENQ_QNAME DS CL8 QNAME SMF87ENQ_RNAME DS CL256 Rname Page 25 of 27

26 Appendix A SMF 87 Subtype 1 fields (OA42221) Details: QSCAN Section (Page 1) SMF87QSCAN DSECT SMF87QSCAN_EYE DS CL8 Addressability derived from address of SMF87RCD + SMF87DEF_QSCAN_OFF + (SMF87DEF_QSCAN_LEN * (index-1)) Service eye-catcher. Refer to constants beginning with SMF87QSCAN_EYE. SMF87QSCAN_VERSION DS F Qscan section version SMF87QSCAN_SCANACTION DS X Requested scan action. Refer to constants beginning with SMF87QSCAN_SCANACTION SMF87QSCAN_FLAGS DS 0X SMF87QSCAN_QNAME_SPECIFIC EQU X'80' Specific Qname? SMF87QSCAN_RNAME_SPECIFIC EQU X'40' Specific Rname? ORG SMF87QSCAN_FLAGS+1 SMF87QSCAN_QNAMELEN DS X Qname length SMF87QSCAN_RNAMELEN DS X Rname length SMF87QSCAN_MINWAITERS DS F Minimum waiters SMF87QSCAN_QNAME DS CL8 Requested Qname. If not specified on request, then zeroes SMF87QSCAN_RNAME DS CL256 Requested Rname. If not specified on request, then zeroes. For length, refer to SMF87QSCAN_RNAMELEN SMF87QSCAN_LEN EQU *-SMF87QSCAN Page 26 of 27

27 Appendix A SMF 87 Subtype 1 fields (OA42221) Details: QSCAN Section (Page 2) Subtype 1 records contain the same header, self-defining section, and requester section as subtype 2 They are single request records Page 27 of 27